WO2004018338A1

WO2004018338A1 - Method and device for stacking flat items to be posted in a stack receiving installation

Info

Publication number: WO2004018338A1
Application number: PCT/DE2003/002186
Authority: WO
Inventors: Dietmar Oexle; Rolf-Peter Skrdlant
Original assignee: Siemens Aktiengesellschaft
Priority date: 2002-08-13
Filing date: 2003-07-01
Publication date: 2004-03-04
Also published as: DE10236952B3; EP1530545B1; DE50312833D1; EP1530545A1; JP2005538007A

Abstract

According to the invention, the items to be posted are held by a stacking support (11) which can be displaced in a stacking direction and is coupled to a flush-mounted strip (9) on which the stack is arranged, and by a parallel stacking wall (7) which is located in a vertical position on the stacking spot, oriented towards an abutment wall (8). Said items to be posted are supplied and stacked by means of stacking belts (1, 2) and a stacking roll (4) which projects from the stacking wall (7) and is located at the entrance to the stack receiving installation, close to the abutment wall (8), said stacking roll (4) being mounted in a deflectable manner. A connecting element (5) is used to connect the stacking roll housing to the force transducer of a device for measuring the stacking pressure perpendicularly to the resulting belt force exerted on the stacking roll (4).

Description

description

Method and device for stacking flat mail items in a stack holder

The invention relates to a method and a device for stacking flat mail items in a stack holder according to the preambles of claims 1 and 6.

The shipments of different formats should all be aligned exactly on two edges.

For each consignment to be stacked, the force of the stack against the stacking roll (stacking pressure) must be optimally adjusted so that each consignment reaches the stop wall and its front and bottom edges are exactly aligned with the consignments that have already been stacked. The manipulated variable for regulating the stack pressure on the stacking roller is the advance of the movable stacking support, with which an underfloor belt can also be coupled. Stacking a shipment increases the stack pressure and can be reduced or optimally adjusted by moving the stack away from the stacking roller or by advancing the underfloor belt with the stacking support. In order to regulate the stack pressure, it is necessary to measure it.

According to the prior art, one or more force measuring devices are located on the stacking wall in the surrounding area of the stacking roller. For example, DE 195 47 292 A1 describes an intermediate stacker in which one or more spring-loaded levers are arranged near the stacking roller for measuring the stacking pressure, and the stack of mail pushes against it. The levers actuate switches which emit switching signals for driving the stack support with the underfloor belt. As soon as a certain minimum pressure acts on the lever or levers, a signal to move the underfloor belt and the stack support away from the stacking roller is triggered. If a certain min If the pressure drops below the minimum pressure, the underfloor belt with the stack support remains in the position it has now assumed.

For the optimal stacking of a consignment, the force between the stack and the stacking roll ("stacking pressure") is decisive, because the amount of friction between the consignment and the stacking roll (or the stacking belt) is directly dependent on this and because the force that causes the shipment of the shipment is exerted on the shipment via the stacking roller (or the stacking belt).

However, the previously known solution only enables the pressure between the stack and one or more contact points of the stack (lever) to be measured on the stack wall in the surrounding area of the stack roller (that is to say on the force measuring devices which only bypass the function-relevant force flow via the stack roller represent). This means that a direct measurement of the stack pressure is not possible, but only a rough estimate of the stack pressure using the measured force shunt.

The invention is therefore based on the object to provide a method and a device for stacking flat articles, in which the ^'more accurately be controlled stacking Measured is.

According to the invention the object is achieved by the features of claims 1 and 6.

The stack pressure is measured directly on the stack roller approximately perpendicular to the direction of the resulting belt force acting on the stack roller via a deflection of the stack roller. For this purpose, the deflectable stacked roller bearing is connected to the force transducer via a connecting element for power transmission

Force measuring device for measuring the stack pressure connected perpendicular to the resulting belt force. As a result, the stack pressure acting on the stacking roller is not falsified by force shunts. Because the stacking roller next to the stack pressure has to also include the resultant belt force, has the relatively small stack pressure from the large resultant belt force that is not constant and ^sons' t would distort the measurement result, are separated. This is done by only measuring the part of the stack pressure that is approximately perpendicular to the resulting belt force, so that the force directions are vectorially decoupled.

Advantageous embodiments of the invention are presented in the subclaims.

It is therefore advantageous to provide a bending beam with strain gauges in the force measuring device, the deformation of which serves as a measure of the stack pressure, approximately perpendicular to the resulting belt force. With this measuring principle with minimal measuring path, disturbing forces due to displacements of the force direction caused by the measuring path are largely avoided.

It is also advantageous if the stacking roller can only be deflected approximately perpendicularly to the direction of the resulting belt force.

In order to compensate for any geometric inaccuracies or the resulting tensions and to transmit no transverse forces to the force measuring device, the force is transmitted from the stacking roller to the bending beam

Force measuring device advantageously via a connecting element which is stiff in the force transmission direction approximately perpendicular to the resulting belt force and perpendicular to it is flexible. It is also advantageous to mount the force measuring device in an adjustable manner on a slide in order to compensate for preloads caused by assembly or tolerance.

The deflection of the stacking roller is advantageously achieved in that the stacking roller bearing is fastened on a movable rocker arm.

So that the direction of the resulting belt force is not changed as a result of a shipment by lifting the stacking belt from a deflecting roller located in front of the stacking roller in the transport direction, as a result of which interference forces are briefly generated, it is advantageous to carry out the measurement of the stacking pressure if there is no follow-up shipment between the stacking belt and the pulley. If this is not possible, the changed direction of the resulting belt force, depending on the thickness of the subsequent mailing, can be taken into account in the calculation of the force.

The invention is then explained in more detail in an exemplary embodiment with reference to the drawing.

1 shows a plan view of the stacking device;

2 shows a perspective view of the stacking roller with force measuring device obliquely from below;

3 shows a perspective view of the stacking roll with a force measuring device obliquely from above.

As can be seen in FIG. 1, the mail items are transported one after the other and clamped between the stacking belts 1, 2 in a standing position in the direction of the stacking roll 4. So that . stacking can take place, the stacking belt 2 directed towards the stack is deflected in front of the stacking device via a deflection roller 3, whereas the other stacking belt 1 is only deflected via the stacking roller 4. The mailings are directed due to their kinetic energy and frictional forces along the stacking belt 1 to the stacking roll 4 to the stacking support 11 located there, if no mailing has been stacked, or directed against the last stacked mailing of the stack at an acute angle and then held between the stack support 11 and a stack wall 7 parallel thereto, from which the stack roller 4 protrudes somewhat. The stack pressure that prevails between the uppermost shipment of the stack and the stacking roll 4 must be so great that each shipment arrives safely between the stacking roll 4 and the stacking support 11 or the uppermost shipment of the stack until the stop wall 8 stops which the kinetic energy of the broadcast is reduced. So that the stack pressure does not become too high after stacking a shipment, the stack support 11 and the stack support in the form of an underfloor belt 9 must be moved away from the stacking point.

This is done by moving the driven underfloor belt 9 and the stack support 11 coupled to it in dependence on the measured stack pressure via a control device, not shown. The coupling takes place via slot-shaped recesses 12 in the underfloor belt 9 and the stack support 11 shaped in such a way that it can anchor itself in one of the recesses 12. Since the stack support 9 can be pivoted upwards on an axis 10 located on the stop wall 8, the stack can be pushed out during unloading after the stack support 11 has been pivoted up. Then the stack support 11 is pushed back on the axis 10 to the stacking roller 4 and swiveled down again and anchored in the corresponding recess 12 of the underfloor belt 9. Then there is a new batch cycle. The stack pressure measurement is carried out directly on the deflectable stack roller 4. Since the strong resulting belt force F _{R also} acts on the stack roller 4, the stack pressure F _s, which is small in relation to this, must the belt force F _R are decoupled from the stacking roller 4. This is achieved by measuring only the component F _S g approximately perpendicular to the direction of the resulting belt force F _R from the stack pressure F _s . The two force directions are therefore vectorially independent of one another.

In order to ensure this, the stacking roller 4 is mounted in such a way that a minimal deflection approximately perpendicular to the resultant of the belt force F _R (ie in the direction of F _ss ) can take place with a minimal force. For this purpose, the stacking roller 4 is pivotally mounted on a movable rocker 14 with minimized friction. Storage of the stacking roller 4 on an element that is easily deformable in this direction is in principle also possible. In the direction of the possible deflection, the force component F _ss is measured by a force measuring device which is positively connected to the rocker 14 of the stacking roller 4.

The force component F _{ss is} transmitted to the force measuring device by a connecting element 5, which is designed to be particularly flexible about the two axes perpendicular to the force measuring direction in order to compensate for any geometric inaccuracies or the resulting stresses and no transverse forces on the force measuring device transferred to. In the direction of force transmission, the connecting element 5 is made as rigid as possible. A measuring principle with a minimal measuring path, for example by means of a bending beam 6 with strain gauges, is used for force measurement in order to minimize interference forces due to the displacement of the force device due to the measuring path. The Ver inding element 5 is, as can be seen in Figures 2 and 3, fastened with screw connections on the bending beam 6 and on a fastening element of the rotatably mounted rocker 14. The bearing 13 of the stacking roller 4 is also located on the rocker 14. In order to compensate for the prestressing of the force measuring device in the measuring direction due to on-site and tolerance, the bending beam 6 is fastened on a lock 15 that can be locked in the measuring direction.

The force component F _ss changes depending on the size of the angle β between the resulting belt force F _R and the stack wall 7. At an angle β of approximately <30 °, it is still large enough to achieve meaningful measurement results. If the force measuring direction is not arranged in the direction of movement of the stacking roller 4, but rather in the direction of the stacking pressure Fg to be measured, cosß goes against 1 and thus F _ss against Fg. However, with minimal deflection, the direction of movement of the stacking roller 4 no longer corresponds to the force measuring direction , whereby with increasing measuring path

Tension or interference can arise. These can be largely compensated for by the connecting element 5. Nevertheless, the force measurement is carried out approximately in the direction of movement of the stacking roller 4, because this ensures the vectorial separation of F and Fg and, for example, fluctuations in the resulting belt force F due to different belt tension cause almost no interference forces in the force measurement direction.

It is advantageous to carry out the measurement of the stack pressure Fg at a point in time when there is no follow-up shipment between the stacking belt 1 and the deflection roller 3, because by lifting the stacking belt 1 off the deflection roller 3 (depending on the thickness of the follow-up shipment) the direction of the resulting belt - Force F _{R is} slightly influenced and therefore briefly

Interference forces act on the force measuring device.

In order to be able to change the stacking belt 1 without great effort and without tools, the rocker 14 is attached below the stacking roller 4 (between the stacking roller and letter plate) so that the stacking belt 1 is not locked in. So that the stacking wall 7 does not have to be disassembled when changing the belt, it is provided with a hinged door which enables the stacking belt 1 to be removed upwards.

Claims

claims

1. A method for stacking flat mail items in a stack receptacle, in which the mail items are supported by a stack support (11) which can be moved in the stacking direction and which is coupled to an underfloor belt (9) on which the stack is positioned, and a stack wall (7 ) are held in a standing position at the stacking point, aligned with a stop wall (8), the consignments individually one after the other by means of stacking belts (1, 2) of a shroud system and one at the entrance of the stack holder near the stop wall (8) located and from the stacking wall (7) projecting stacking roller (4), via which one of the stacking belts (1) is deflected, fed and stacked, the mail items at an acute angle to the longitudinal direction of the stacking support (11) on this or the last one be stacked broadcast are passed up to the stop wall (8), le with ^'a force measuring device for the stacking pressure at the Einstapelstel- that a with the drive of Underfloor belt (9) connected device for regulating the stack pressure is connected, characterized in that the stack pressure directly on the stacking roller (4) approximately perpendicular to the direction of the resulting belt force on the stacking roller (4) via a

Deflection of the stacking roller (4) is measured.

2. The method according to claim 1, so that the deflection of the stacking roller (4) is transferred to a bending beam (6) with strain gauges, the deformation of which is approximately perpendicular to the resulting belt force as a measure of the stacking pressure.

3. The method according to claim 2, characterized in that the stacking roller (4) only approximately perpendicular to the direction of the resulting belt force is deflectable.

4. The method of claim 2, d a d u r c h g e k e n n z e i c h n e t that the power transmission from the deflectable stacking roller (4) on the bending beam (6)

Force measuring device takes place via a connecting element (5), the connecting element (6) being designed stiff in the force transmission direction approximately perpendicular to the resulting belt force, and perpendicular to it being flexible.

5. The method according to claim 1, characterized in that the stack pressure is only measured when there is still no subsequent shipment between stacking belts (1) and a deflection roller (3) located in front of the stacking roller (4) for the other stacking belt (2). located.

6. Device for stacking flat mail items in a stack receptacle in a standing position on an underfloor belt (9) which can be moved in the stacking direction, aligned on a stop wall (8), with a stacking support (11) coupled to the underfloor belt (9) and a parallel stacking wall (7) at the stacking point, with stacking lines (1, 2) of a cover tape system and a stacking roller (4) located at the entrance to the stacking receptacle near the stop wall (8) and protruding from the stacking wall (7) , via which one of the stacking belts (1) is deflected, for feeding the consignments one after the other and stacking them, the consignments being at an acute angle to the longitudinal direction of the stacking support (11) or the last consignment already stacked up to the stop wall (8) are passed, with a force measuring device for the stack pressure at the stacking point, which is connected to a device connected to the drive of the underfloor belt (9) for regulating the stack oil pressure is connected, characterized in that that the stacking roller (4) is supported in a deflectable manner and the stacking roller bearing is connected to the force transducer of the force measuring device for measuring the stacking pressure perpendicular to the resulting belt force on the stacking roller (4) via a connecting element (5).

7. The device as claimed in claim 6, so that a bending beam (6) with strain gauges is provided as the force transducer in the force measuring device, the deflection of which serves as a measure of the stack pressure, approximately perpendicular to the resulting belt force on the stacking roller (4).

8. Device according to claim 6, so that the stack roller (4) can only be deflected onto the stack roller (4) approximately perpendicularly to the direction of the resulting belt force.

9. Device according to claim 7, characterized in that the bearing of the deflectable stacking roller (4) is coupled via a connecting element (5) to the bending beam (6) of the force measuring device, the connecting element (5) being approximately perpendicular to the resulting belt force in the direction of force transmission on the stacking roll (4) is stiff and perpendicular to it flexible.

10. Device according to claim 6, so that the force measuring device is arranged to be adjustable.

11. The device according to claim 6, so that the stack roller bearing (13) is fastened to a movable rocker (14) which is connected to the connecting element (5).